On the operatic stage she performed the roles of Adelaide (Lotario) at the Göttingen International Handel Festival, Dalinda (Ariodante) at the London Handel Festival, Asteria (Tamerlano) at Buxton Festival, Adele (Die Fledermaus) directed by John Copley, Königin der Nacht (Die Zauberflöte) and Clara (La Vie Parisienne) at the RCM International Opera School, Eurilla (Orlando Paladino) with Opéra de Fribourg, Galatea (Acis and Galatea) with Opéra Louise, Nanetta (Falstaff) at Woodhouse Opera, and Lauretta (Gianni Schicchi) at Les Azuriales Festival. In 2011 she premiered the role of Mina in Thierry Besançon's Dracula ou la Symphonie Inachevée in Switzerland.

In 2016 she was awarded the Michael Normington Prize in the Handel Singing Competition, First Prize in the Lies Askonas Competition, Second Prize in the Joan Chissell Schumann prize for voice and piano, and in 2015 she won the First Prize in the Göttinger Reihe Historischer Musik Competition with Abchordis Ensemble, that she co-founded in 2011. Their first recording, 'Stabat Mater', was published in 2016 by Sony DHM.

She works regularly with her pianist partner João Araújo, with whom she founded Duo Dalma.

A Samling Artist and a Migros cultural Percentage Soloist, she has been supported by the Leenaards, Dénéréaz, Colette Mosetti and Friedl Wald Foundations and by the Drake Calleja Trust and the Josephine Baker Trust.

After a Bachelor in Music at the Haute Ecole de Musique de Lausanne with a Prize for the best recital, Marie studied at the Royal College of Music where she graduated with First Class Honours in 2014, before joining their International Opera School under Amanda Roocroft, graduating in 2016 with an Artist Diploma in Opera. She studies with Rachel Bersier in Neyruz.

Future appearances include recitals in Switzerland with Duo Dalma, Mozart's Requiem with Michel Corboz, Brahms' Requiem with Daniel Reuss, Bach's St. Matthew Passion with Laurence Cummings at the London Handel Festival, and her debut at Casa da Música (Porto) with Orquestra Barocca Casa da Música and Laurence Cummings.

"Vocal honours were easily taken by Swiss soprano Marie Lys as Adelaide, with a clear, penetrating voice and excellent technique. Her singing was an almost textbook display of Baroque vocalism, with mostly straight tone but judicious use of vibrato for colouration; pretty trills for emphasis, well articulated accurate coloratura and some lovely cadenzas. She also brought dramatic skills to bear, standing up to the nasty bullying Berengarios with furious defiance. “Scherza in mar la navicella” was a particular tour de force." [Bachtrack - May 2017]

"Particularly impressive were Marie Lys and Owen Willetts singing Asteria and Andronico respectively. Lys sang with great versatility, showing a silvery crystalline soprano in glorious trills that bounced round the higher register like a kangaroo on speed. Impeccable diction and a captivating stage presence that veered from imperious to ferocious with alarming rapidity brought the character to life. [...] The duet in Act III between these two splendid singers was the highlight of the evening." [Bachtrack - July 2016]

"Marie Lys brought great charm to the role of Asteria. Whilst she had that combination of lightness of touch and killer technique needed by any Handel heroine, Lys also brought out the character's great strength. There was a toughness to her performance which showed that she clearly was her father's daughter. She and Willetts were wonderfully tender in their duet, rightly one of the loveliest things in the opera, yet you never doubted for one moment that Lys's Asteria had the strength of character to kill Tamerlano on their marriage bed, and her strong sense of moral uprightness came out both in her demeanour and in her musical performance." [Planet Hugill - July 2016]

"Marie Lys proved herself a singer of impressive range and real passion from the start, and found the dimension of feistiness in her role as noble daughter – the father-daughter relationship is one that’s rarely explored with such truthfulness and emotional power in opera of this period, and she and Nilon caught it well." [Manchester Classical Music - July 2016]

"Lys conveyed a vibrant sense of Dalinda's youth. Her feel for Handel's music was strong with some finely accurate fioriture, culminating in a stunning show-stopping account of Dalinda's final aria, which showed that Lys can't just sing pinpoint coloratura but can really perform it." [Planet Hugill - March 2016]